During machining, fabrication and other fixturing operations, mechanical workpieces are held in a fixture on one or more rest pads by one or more clamping devices. The workpieces need to have solid contact with rest pads to ensure dimensional conformance and stability of the workpieces during such operations as manufacturing, machining, tacking, welding or the like.
A problem that typically arises with rest pads, though, is that conventional fixtures require operators to manually ensure the positioning of the workpiece on the rest pads so that the appropriate contact force and workpiece positioning is achieved and/or maintained. For example, conventional fixtures typically require operators to use a filler gauge to check for any gaps between the workpiece and rest pads so that the appropriate contact force is achieved and/or maintained. If the appropriate contact force and workpiece positioning is not achieved and/or maintained, a workpiece might be constructed improperly during assembly operations resulting in the workpiece being warped, the workpiece being misaligned, the generation of waste parts, workpiece damage, injury to workers, damage to a manufacturing machine, and/or the like.
European Patent Publication EP2103377A1 (EP '377), entitled “Method and Apparatus for Checking Proper clamping of Workpieces in a CNC Machine,” purports to prevent the machining of incorrectly positioned workpieces by continuously checking the proper clamping of work pieces. The EP '377 publication describes direct pressure measurement by wireless pressure transmitters capable of detecting and continuously transmitting pressure information to the CNC machine in hidden time. However, the EP '377 publication does not produce dynamic fixturing feedback and the ability to dynamically adjust individual forces to account for a dimensional feedback. Using air sensors to detect a gap in contact does not address the needs contemplated by the disclosed system.
Accordingly, there is a need for an improved system to monitor and record contact force information. In this regard, the shortcomings of the prior art are addressed by the various aspects in the disclosure.